Muhammadu Buhari, Nigeria's embattled leader

As Nigerian President Muhammadu Buhari seeks re-election, he must do without the decisive factor behind his victory four years ago – the promise of a clean break from the past.

Back then, he represented a new broom, the symbol of his party. He had never been democratically elected despite having tried three times, and his public image – as a dour, incorruptible disciplinarian – was based on a 20-month stint as military leader, back in the 1980s.

He campaigned as a born-again democrat, vowing to root out corruption, revive the economy and defeat the Islamist Boko Haram insurgency. An electorate worried about corruption, insecurity and the economy took him at his word, making him the first Nigerian opposition candidate to defeat an incumbent president.

Mr Buhari’s victory in 2015 was not just an endorsement of his platform but also an indictment of the politics that preceded him. This election, in turn, will pass judgement on the politics of his term. He can no longer promise a clean break from a past of which he is a part.

His record in office is mixed. Mr Buhari’s critics say that the very attributes that won over voters four years ago – his strictness and inflexibility – have emerged as liabilities. They accuse him of autocratic leanings as well as a disastrous tendency towards…